Magnetic separation of electrochemical cell materials

ABSTRACT

A process and system for the separation of materials from electrochemical cells is disclosed. Electrode materials are removed from electrochemical cells and separated into constituent active materials using magnetic separation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation application and claims thebenefit of the filing date under 35 U.S.C. § 120 of co-pending U.S.patent application Ser. No. 13/435,143, filed on Mar. 30, 2012, whichissued on Oct. 13, 2015 as U.S. Pat. No. 9,156,038. U.S. patentapplication Ser. No. 13/435,143 is incorporated by reference into thisspecification.

TECHNICAL FIELD

This specification generally relates to the separation of recyclableelectrode materials from electrochemical cell scrap. More specifically,this specification relates to the separation of recyclable electrodematerials from electrochemical cell scrap to form recycled materialconcentrates that may be directly re-used in new electrochemical cellmanufacturing.

BACKGROUND

Batteries and other devices comprising electrochemical cells are anever-present part of modern consumer and industrial technology. Forexample, lithium-ion, nickel-metal hydride, nickel-zinc, nickel-cadmium,and lead-acid rechargeable batteries (i.e., secondary batteries) areused in applications including, but not limited to, gasoline-poweredautomobiles, hybrid electric vehicles, electric vehicles, industrialequipment, power tools, and consumer electronics (e.g., notebookcomputers, tablet computers, cellular telephones and smart phones, amongother rechargeable electronic devices). In addition, single-usedisposable batteries (i.e., primary batteries such as, for example,zinc-carbon batteries and alkaline batteries) are used in a vast numberof electrical and electronic device applications. Accordingly, thewidespread use of batteries and other devices comprising electrochemicalcells (e.g., electric double-layer capacitors, also known assupercapacitors or ultracapacitors) causes the generation of large scrapbattery waste streams.

As the use of batteries and other electrochemical cells becomes morewidespread resulting in larger scrap device waste streams, the recyclingof scrap devices becomes increasingly important from the perspective ofboth environmental sustainability and manufacturing economics. Becausebatteries and other electrochemical cell devices may comprise scarcematerials and various chemicals posing environmental contaminationconcerns, the recycling of scrap devices is important to advance goalsof environmental protection and sustainability. Moreover, becausebatteries and other electrochemical cell devices may comprise relativelyexpensive materials such as nickel, cobalt, lithium metal compounds, andother expensive metals, alloys, and compounds, the recycling of scrapdevices is important for reducing the costs of manufacturing newbatteries and electrochemical cells, which would otherwise require theuse of virgin materials.

SUMMARY

In a non-limiting embodiment, a process for the separation of materialsfrom electrochemical cells is described. The process comprisessubjecting a slurry comprising electrode active material particles to amagnetic field. The magnetic field is of sufficient magnetic fieldintensity to magnetize paramagnetic particles in the slurry. Themagnetized particles are separated from the slurry using magnetic forceinduced between the magnetized particles and an active magnetic surfacein contact with the slurry.

In another non-limiting embodiment, a process for the separation ofmaterials from electrochemical cells comprises removing electrode activematerials from electrochemical cells. The electrochemical cells compriselithium ion electrochemical cells. A slurry is formed comprising theelectrode active materials. The slurry comprises lithium metalcompounds. The slurry is subjected to a magnetic field of sufficientmagnetic field intensity to magnetize particles in the slurry. Themagnetized particles comprise at least one lithium metal compound. Themagnetized particles are separated from the slurry using magnetic forceinduced between the magnetized particles and an active magnetic surfacein contact with the slurry.

In another non-limiting embodiment, a process for the separation ofmaterials from electrochemical cells comprises comminutingelectrochemical cells. The electrochemical cells comprise lithium-ionelectrochemical cells. The comminuted electrochemical cells are screenedto separate electrode active material particles from otherelectrochemical cell components. The electrode active material particlescomprise two or more lithium metal compounds. The electrode activematerial particles are mixed with a carrier fluid to produce a slurry.The slurry is subjected to a magnetic field of sufficient magnetic fieldintensity to magnetize paramagnetic particles in the slurry. Themagnetized particles are separated from the slurry using magnetic forceinduced between the magnetized particles and an active magnetic surfacein contact with the slurry. The separated particles comprise one of thetwo or more lithium metal compounds. The two or more lithium metalcompounds are collected as separated electrode active materialconcentrates.

It is understood that the invention disclosed and described in thisspecification is not limited to the embodiments summarized in thisSummary.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features and characteristics of the non-limiting andnon-exhaustive embodiments disclosed and described in this specificationmay be better understood by reference to the accompanying figures, inwhich:

FIG. 1 is a flowchart diagram illustrating a process for the separationand concentration of electrode active materials from electrochemicalcells;

FIG. 2 is a schematic diagram of a high-intensity magneticfiltration/separation system;

FIG. 3 is a schematic diagram of a high-intensity magneticfiltration/separation system comprising a recycle feature;

FIG. 4 is a process and system flow diagram illustrating a plurality ofhigh-intensity magnetic filters/separators connected in series;

FIG. 5A is a schematic diagram illustrating a concurrent flow tank drumseparator; FIG. 5B is a schematic diagram illustrating acounter-rotation flow tank drum separator;

FIG. 6 is a process and system flow diagram illustrating a plurality ofdrum separators connected in series;

FIG. 7 is a process and system flow diagram illustrating a plurality ofdrum separators connected in parallel;

FIG. 8 is a flowchart diagram illustrating a staged magnetic separationof electrode active materials utilizing increasing magnetic fieldintensities;

FIG. 9 is a flowchart diagram illustrating a staged magnetic separationof electrode active materials utilizing decreasing magnetic fieldintensities;

FIGS. 10 and 11 are scatter-plot graphs of induced magnetization versusexternally applied magnetic field for various lithium metal compounds;

FIG. 12 is a bar graph of magnetic susceptibility values for variouslithium metal compounds;

FIGS. 13 through 20 are scatter-plot graphs of material concentrationsand recoveries versus percentage intensity of magnetic separation fieldfor test separations of lithium metal compounds in accordance withExample 2;

FIGS. 21 through 25 are scatter-plot graphs of material concentrationsand recoveries versus percentage intensity of magnetic separation fieldfor test separations of electrode active materials obtained from aprismatic pouch lithium-ion battery;

FIGS. 26 and 27 are process and system flow diagrams illustratingexemplary lithium-ion electrochemical cell recycle processes andsystems;

FIG. 28 is a flowchart diagram illustrating a staged magnetic separationof electrode active materials utilizing increasing magnetic fieldintensities;

FIG. 29 is a flowchart diagram illustrating a staged magnetic separationof electrode active materials utilizing decreasing magnetic fieldintensities; and

FIG. 30 is a process and system flow diagram illustrating an exemplarymixed electrochemical cell recycle process and system.

The reader will appreciate the foregoing details, as well as others,upon considering the following detailed description of variousnon-limiting and non-exhaustive embodiments according to thisspecification.

DESCRIPTION

Various embodiments are described and illustrated in this specificationto provide an overall understanding of the structure, function,properties, and use of the disclosed processes and systems. It isunderstood that the various embodiments described and illustrated inthis specification are non-limiting and non-exhaustive. Thus, theinvention is not limited by the description of the various non-limitingand non-exhaustive embodiments disclosed in this specification. Thefeatures and characteristics described in connection with variousembodiments may be combined with the features and characteristics ofother embodiments. Such modifications and variations are intended to beincluded within the scope of this specification. As such, the claims maybe amended to recite any features or characteristics expressly orinherently described in, or otherwise expressly or inherently supportedby, this specification. Further, Applicant(s) reserve the right to amendthe claims to affirmatively disclaim features or characteristics thatmay be present in the prior art. Therefore, any such amendments complywith the requirements of 35 U.S.C. § 112, first paragraph, and 35 U.S.C.§ 132(a). The various embodiments disclosed and described in thisspecification can comprise, consist of, or consist essentially of thefeatures and characteristics as variously described herein.

Any patent, publication, or other disclosure material identified hereinis incorporated by reference into this specification in its entiretyunless otherwise indicated, but only to the extent that the incorporatedmaterial does not conflict with existing definitions, statements, orother disclosure material expressly set forth in this specification. Assuch, and to the extent necessary, the express disclosure as set forthin this specification supersedes any conflicting material incorporatedby reference herein. Any material, or portion thereof, that is said tobe incorporated by reference into this specification, but whichconflicts with existing definitions, statements, or other disclosurematerial set forth herein, is only incorporated to the extent that noconflict arises between that incorporated material and the existingdisclosure material. Applicant(s) reserve the right to amend thisspecification to expressly recite any subject matter, or portionthereof, incorporated by reference herein.

In this specification, other than where otherwise indicated, allnumerical parameters are to be understood as being prefaced and modifiedin all instances by the term “about”, in which the numerical parameterspossess the inherent variability characteristic of the underlyingmeasurement techniques used to determine the numerical value of theparameter. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter described in this specification should at leastbe construed in light of the number of reported significant digits andby applying ordinary rounding techniques.

Also, any numerical range recited in this specification is intended toinclude all sub-ranges of the same numerical precision subsumed withinthe recited range. For example, a range of “1.0 to 10.0” is intended toinclude all sub-ranges between (and including) the recited minimum valueof 1.0 and the recited maximum value of 10.0, that is, having a minimumvalue equal to or greater than 1.0 and a maximum value equal to or lessthan 10.0, such as, for example, 2.4 to 7.6. Any maximum numericallimitation recited in this specification is intended to include alllower numerical limitations subsumed therein and any minimum numericallimitation recited in this specification is intended to include allhigher numerical limitations subsumed therein. Accordingly, Applicant(s)reserve the right to amend this specification, including the claims, toexpressly recite any sub-range subsumed within the ranges expresslyrecited herein. All such ranges are intended to be inherently describedin this specification such that amending to expressly recite any suchsub-ranges would comply with the requirements of 35 U.S.C. § 112, firstparagraph, and 35 U.S.C. § 132(a).

The grammatical articles “one”, “a”, “an”, and “the”, as used in thisspecification, are intended to include “at least one” or “one or more”,unless otherwise indicated. Thus, the articles are used in thisspecification to refer to one or more than one (i.e., to “at least one”)of the grammatical objects of the article. By way of example, “acomponent” means one or more components, and thus, possibly, more thanone component is contemplated and may be employed or used in animplementation of the described embodiments. Further, the use of asingular noun includes the plural, and the use of a plural noun includesthe singular, unless the context of the usage requires otherwise.

At present, the most commercially significant secondary battery systemsare lead-acid, nickel-cadmium, nickel-metal hydride, and lithium-ion. Anoverview of the recycling of these battery systems is described in thefollowing references, each of which is incorporated by reference intothis specification:

-   Stevenson, M., “Recycling: Lead-Acid Batteries: Overview,”    Encyclopedia of Electrochemical Power Sources, pp. 165-178, 2009,    Elsevier B. V., Editor-in-Chief: Jürgen Garche.-   Sloop, S. E., Kotaich, K., Ellis, T. W., & Clarke, R., “Recycling:    Lead-Acid Batteries: Electrochemical,” Encyclopedia of    Electrochemical Power Sources, pp. 179-187, 2009, Elsevier B. V.,    Editor-in-Chief: Jürgen Garche.-   Kotaich, K. & Sloop, S. E., “Recycling: Lithium and Nickel-Metal    Hydride Batteries,” Encyclopedia of Electrochemical Power Sources,    pp. 188-198, 2009, Elsevier B. V., Editor-in-Chief: Jürgen Garche.-   Scott, K., “Recycling: Nickel-Metal Hydride Batteries,” Encyclopedia    of Electrochemical Power Sources, pp. 199-208, 2009, Elsevier B. V.,    Editor-in-Chief: Jürgen Garche.-   Xu, J., Thomas H. R., Francis R. W., Lum, K. R., Wang, J., Liang,    B., “A review of processes and technologies for the recycling of    lithium-ion secondary batteries,” Journal of Power Sources, Volume    177, January 2008, pp. 512-527.-   S. M. Shin, N. H. Kim, J. S. Sohn, D. H. Yang, Y. H. Kim,    “Development of a metal recovery process from Li-ion battery    wastes,” Hydrometallurgy, Volume 79, Issues 3-4, October 2005, pp.    172-181.-   Junmin Nan, Dongmei Han, Xiaoxi Zuo, “Recovery of metal values from    spent lithium-ion batteries with chemical deposition and solvent    extraction,” Journal of Power Sources, Volume 152, 1 Dec. 2005,    Pages 278-284.-   Rong-Chi Wanga, Yu-Chuan Lina, She-Huang Wub, “A novel recovery    process of metal values from the cathode active materials of the    lithium-ion secondary batteries,” Hydrometallurgy, Volume 99, Issues    3-4, November 2009, Pages 194-201.-   Y. Pranolo, W. Zhang, C. Y. Cheng, “Recovery of metals from spent    lithium-ion battery leach solutions with a mixed solvent extractant    system,” Hydrometallurgy, Volume 102, Issues 1-4, April 2010, Pages    37-42.-   Baoping Xin, Di Zhang, Xian Zhang, Yunting Xia, Feng Wu, Shi Chen,    Li Li, “Bioleaching mechanism of Co and Li from spent lithium-ion    battery by the mixed culture of acidophilic sulfur-oxidizing and    iron-oxidizing bacteria,” Bioresource Technology, Volume 100, Issue    24, December 2009, Pages 6163-6169.-   Li L, Ge J, Wu F, Chen R, Chen S, Wu B, “Recovery of cobalt and    lithium from spent lithium ion batteries using organic citric acid    as leachant,” J. Hazard Mater., 176(1-3), Apr. 15, 2010, pp. 288-93.-   M Contestabile, S Panero, B Scrosati, “A laboratory-scale    lithium-ion battery recycling process,” Journal of Power Sources,    Volume 92, Issues 1-2, January 2001, Pages 65-69.-   Daniel Assumpção Bertuola, Andréa Moura Bernardesa, Jorge Alberto    Soares Tenóriob, “Spent NiMH batteries: Characterization and metal    recovery through mechanical processing,” Journal of Power Sources,    Volume 160, Issue 2, 6 Oct. 2006, Pages 1465-1470.-   Kim, Y, Matsuda, M., Shibayama, A., Fujita, T., “Recovery of LiCoO₂    from Wasted Lithium Ion Batteries by using Mineral Processing    Technology,” Resources Processing, Volume 51, Issue 1, 2004, pp.    3-7.-   U.S. Pat. No. 6,261,712, Jul. 17, 2001.-   International Patent Application Publication No. WO 2008/022415 A1,    Feb. 28, 2008.

Industrial-scale processes for the reclamation and recycling of activeelectrochemical cell materials (i.e., the electrode active materials)generally fall into two categories: pyrometallurgical processes andhydrometallurgical processes. Pyrometallurgical processes involve thehigh-temperature smelting of scrap electrochemical cells to producevarious alloys, metallic oxides, carbon, and flue gases.Pyrometallurgical processes are very energy-intensive and produce largequantities of slag, dross, fly ash, and other waste materials that mustbe disposed of or further processed. Hydrometallurgical processesgenerally employ aggressive chemicals such as strong acids and/or strongbases to dissolve metals, alloys, and/or inorganic metal compounds, suchas metal oxides, and extract or leach the active electrochemical cellmaterials from scrap electrochemical cells. To recover theextracted/leached materials, the ion-rich leach solutions that resultfrom extraction treatment must be further processed by techniques suchas counter-solvent extraction, chemical precipitation, chemicaldeposition, and/or electrowinning to recover the dissolved metals in achemically reduced or other useful form. Hydrometallurgical processesrely on inorganic solution chemistry and solution post-processing and,therefore, may pose environmental or workplace health and safetyconcerns arising from solution waste streams.

Pyrometallurgical and hydrometallurgical processes both suffer fromvarious additional disadvantages, particularly in the context ofrecycling electrode materials from lithium-ion batteries. In both typesof recycling processes, the electrode active materials are recovered instructurally-modified and chemically-modified forms that cannot bedirectly re-used to manufacture electrodes for new electrochemicalcells. For example, during pyrometallurgical recycling of lithium-ionbatteries, the cathode (i.e., positive electrode) active materials(e.g., LiCoO₂, LiMn₂O₄, LiFePO₄, LiNiO₂, LiNiCoMnO₂,LiNi_(1/3)Co_(1/3)Al_(1/3)O₂, LiNi_(0.8)Co_(0.2)O₂,LiNiO_(0.833)Co_(0.17)O₂) are chemically converted into Co—Fe—Ni—Mnalloys, which are recovered as the smelting product, and lithium oxides,which are lost to slag, fly ash, and dross. Likewise, duringhydrometallurgical recycling of lithium-ion batteries, the cathodeactive materials are chemically converted into various oxides,hydroxides, and oxyhydroxides of the constituent metals, which mustundergo substantial post-processing, separation, purification, andchemical modification and synthesis to reconstitute cathode activematerials. Analogous issues are associated with the pyrometallurgicaland hydrometallurgical recycling of electrode active materials fromnickel-metal hydride, lead-acid, and other electrochemical cellchemistries.

Pyrometallurgical and hydrometallurgical recycling processes both failto recover the electrode active materials in the structural and chemicalforms present in the original electrochemical cells. The processes andsystems described in this specification address this issue, amongothers, by enabling the separation of recyclable anode and cathodeactive materials from electrochemical cell scrap in the structural andchemical forms present in the original electrochemical cells. Theprocesses and systems described in this specification may form recycledmaterial concentrates that may be directly re-used in newelectrochemical cell manufacturing. In this manner, the processes andsystems described in this specification may eliminate the need forpyrometallurgical and hydrometallurgical recycling processes to recoverelectrode active materials from scrap electrochemical cells.Alternatively, in various non-limiting embodiments, the processes andsystems described in this specification may be used in combination withpyrometallurgical, hydrometallurgical, and other recycling processes andsystems.

The embodiments described in this specification comprise the magneticseparation of magnetized particles comprising electrode active materialsfrom scrap electrochemical cells. It is understood that scrapelectrochemical cells include, but are not limited to, end-of-life,damaged, or otherwise scrapped batteries and other devices comprisingenergy storing and/or converting electrochemical cells, such as, forexample, electric double-layer capacitors.

When a material is placed in a magnetic field, a magnetization (i.e., anet magnetic dipole moment per unit volume) is induced in the material.The magnetization (M) of a material placed in a magnetic field (H) isdefined by the expression:M=χHwherein χ is the magnetic susceptibility of the material. Magneticsusceptibility is a dimensionless proportionality constant thatindicates the degree of magnetization of a material in response to anexternally applied magnetic field. The magnetic susceptibility of amaterial is an intrinsic physical property. The magnetic susceptibilityof a material provides a measure of how the material will react whenplaced in a magnetic field.

All atomic, ionic, and molecular matter possesses diamagneticproperties, which is the tendency of a material to oppose an externallyapplied magnetic field. Materials that do not have any unpaired electronorbital spin or spin angular momentum are generally diamagnetic.Diamagnetic materials are repelled by an externally applied magneticfield. The magnetic susceptibility values of diamagnetic materials arenegative values, which indicate the repulsion of the materials byexternally applied magnetic fields. Larger absolute values of themagnetic susceptibilities of diamagnetic materials correlate with largerinduced magnetizations and larger repulsive magnetic forces between thediamagnetic materials and an externally applied magnetic field.

Materials with unpaired electrons are paramagnetic. The paired electronscharacteristic of diamagnetic materials are required by the Pauliexclusion principle to have their intrinsic spin magnetic momentsaligned in opposite orientation, causing their magnetic fields to cancelout. Conversely, the unpaired electrons characteristic of paramagneticmaterials are free to align their intrinsic spin magnetic moments in thesame direction as an externally applied magnetic field. Therefore,paramagnetic materials exhibit the tendency to enhance an externallyapplied magnetic field. Paramagnetic materials are attracted by anexternally applied magnetic field. The magnetic susceptibility values ofparamagnetic materials are positive values, which indicate theattraction of the materials by externally applied magnetic fields.Larger values of the magnetic susceptibilities of paramagnetic materialscorrelate with larger induced magnetizations and larger attractivemagnetic forces between the paramagnetic materials and an externallyapplied magnetic field.

In the absence of an externally applied magnetic field, diamagnetic andparamagnetic materials do not exhibit any intrinsic or persistentmagnetization. The materials generally referred to as permanent“magnets” are ferromagnetic materials. Like paramagnetic materials,ferromagnetic materials also have unpaired electrons. However, unlikeparamagnetic materials, ferromagnetic materials exhibit a persistentmagnetization in the absence of an externally applied magnetic field.Ferromagnetism arises from the intrinsic tendency of the unpairedelectrons of these materials to orient parallel to each other (eitherco-parallel or anti-parallel, i.e., ferro- and ferri-magnetism,respectively) to minimize their energy state. Ferromagnetic materialsare characterized by a Curie point temperature above which a givenferromagnetic material loses its ferromagnetic properties becauseincreased thermal motion within the material disrupts the alignment ofthe electron's intrinsic spin magnetic moments.

Materials that are negligibly affected by magnetic fields may bereferred to as non-magnetic materials notwithstanding the fact that suchmaterials are, by definition, diamagnetic or weakly paramagnetic. Thediamagnetic materials found in batteries and other electrochemical celldevices may be considered non-magnetic. These materials include, but arenot limited to, plastics, polymer binders, water, organic solvents,lithium salts, graphite (carbon), cadmium, zinc, copper, gold, silicon,lead and lead compounds, and sulfuric acid. Paramagnetic materials foundin batteries and other electrochemical cell devices include, forexample, aluminum, steel, nickel oxyhydroxide, nickel-metal hydridealloys, and inorganic lithium metal compounds.

Lithium-ion electrochemical cells, for example, generally comprise acathode, anode, separator, electrolyte, and housing. The cathodecomprises an aluminum current collecting plate or foil coated with aparticulate lithium metal compound and a polymeric binder such aspolyvinylidene fluoride. The particulate lithium metal compoundcomprises particles of a lithium metal oxide or lithium metal phosphatesuch as, for example, LiCoO₂, LiMn₂O₄, LiFePO₄, LiNiO₂, LiNiCoMnO₂,LiNi_(1/3)Co_(1/3)Al_(1/3)O₂, LiNi_(0.8)Co_(0.2)O₂, orLiNiO_(0.833)Co_(0.17)O₂. A given lithium-ion electrochemical cellgenerally comprises only one of these cathode active materials becausetheir respective electrochemistries are incompatible. LiCoO₂ is the mostcommon cathode active material in commercial and industrial lithium-ionelectrochemical cells because this material exhibits reliable cathodicperformance, high energy density, low self-discharge rate, long cycletime, and ease of manufacture.

The anodes of lithium-ion electrochemical cells generally comprisecopper current collecting plates or foils coated with particulategraphite and a polymeric binder such as polyvinylidene fluoride. Thecathode and anode are separated by a polymeric separator, such as apolyethylene or polypropylene sheet, and are submerged in theelectrolyte. The electrolyte comprises a lithium salt such as LiPF₆,LiBF₄, or LiClO₄ dissolved in an organic solvent such as ethylenecarbonate, dimethyl carbonate, or diethyl carbonate. The electrolytefunctions as a lithium ion-conducting material that facilitatestransport of lithium ions to-and-from the anode and cathode duringcharging and discharging cycles. For example, a lithium-ionelectrochemical cell employing a LiCoO₂ cathode active material and agraphite anode active material operates in accordance with the followinggeneralized electrochemical half reactions (forward reactioncorresponding to the charging cycle; reverse reaction corresponding tothe discharging cycle):6C+xLi⁺ +xe ⁻

C₆Li_(x)LiCoO₂

Li_((1-x))CoO₂ +xLi⁺ +xe ⁻

Lithium-ion electrochemical cells also comprise a housing, otherstructural components, and packaging, which may be made fromnickel-plated steel, aluminum, and/or plastics. The material compositionof an example lithium-ion secondary rechargeable battery is shown inTable 1.

TABLE 1 Range Example Composition Component (Weight Percent) (weightpercent) Lithium metal compound 25-30 27.5 Steel/nickel 22-27 24.5 Cu/Al12-17 14.5 Graphite 14-18 16.0 Electrolyte 2-6 3.5 Polymer/Plastics12-16 14.0

The processes and systems described in this specification comprise themagnetic separation of magnetized particles comprising electrode activematerials, such as, for example, lithium metal compounds. As usedherein, the term “lithium-metal compound” refers to a compoundcomprising lithium, at least one additional metal or metal oxide, and aninorganic counter ion such as, for example, oxide (O₂ ²⁻) or phosphate(PO₄ ³⁻). In various non-limiting embodiments, a lithium metal compoundmay be represented by the general formula:LiM_(x)N_(z)wherein M is one or more metals selected from the group consisting ofCo, Mn, Ni, Fe, and Al, wherein N is an inorganic counter ion selectedfrom the group consisting of O₂ ²⁻ and PO₄ ³⁻, wherein x ranges fromgreater than zero to two (0<x≤2), and wherein z ranges from one to five(1≤z≤5). In various non-limiting embodiments, a lithium metal compoundmay comprise LiCoO₂, LiMn₂O₄, LiFePO₄, LiNiO₂, LiNiCoMnO₂,LiNi_(1/3)Co_(1/3)Al_(1/3)O₂, LiNi_(0.8)Co_(0.2)O₂, orLiNiO_(0.833)Co_(0.170)O₂. In some non-limiting embodiments, a lithiummetal compound may comprise a compound of the formula:LiNi_(1-y)Co_(y)O₂wherein y ranges from zero to 1 (0≤y≤1).

Electrochemical cell grade lithium metal compounds are used in aparticulate structural form (i.e., powdered form) as the activematerials to produce lithium-ion electrochemical cell cathodes. Powderedlithium metal compounds as a cathode active material may be obtained bycalcining a mixture of a lithium compound powder and one or more metalcompound powders to produce particles of a lithium metal compound. Thelithium compound powder and the metal compound powders are,respectively, compounds that can produce corresponding oxides orphosphates by calcination of the powders. For example, mixtures ofpowdered oxides, hydroxides, carbonates, carbides, phosphates, and thelike, of lithium, cobalt, manganese, nickel, iron, and aluminum,including mixed metal compounds, may be calcined to produce particulatelithium metal compound powders, which may be used to form the cathodeactive material coatings on current collecting plates or foils. Examplesof suitable lithium compounds include Li₂O, Li₂CO₃, and the like.Examples of suitable cobalt compounds include Co(OH)₂, Co₂(CO₃)(OH)₂,Co₂O₃, and the like. Examples of suitable nickel compound includeNi(OH)₂, Ni₂(CO₃)(OH)₂, Ni₂O₃, and the like. Other suitable materialsinclude various manganese, iron, and aluminum oxides, hydroxides, andthe like.

The particulate lithium metal compound powders used to form the activematerial coatings on current collecting plates or foils in lithium-ionelectrochemical cells generally have an average particle size in thenanometer to micrometer range. In various embodiments, lithium-ionelectrochemical cells may comprise cathodes comprising lithium metalcompound powders having average particle sizes in the range of 10nanometers to 1000 micrometers, and often in the range of 1 micrometerto 20 micrometers. For example, some lithium-ion electrochemical cellscomprise tape-casted or painted electrodes comprising virgin(unprocessed) graphite particles having a D90 value of 14 micrometers,and virgin LiMn₂O₄ or LiNiCoMnO₂ having D90 values of 5.4 micrometersand 15.6 micrometers, respectively, wherein the D90 value is theparticle size below which lies 90 percent of the volume of a particlesample.

As described above, a given lithium-ion electrochemical cell generallycomprises only one lithium metal compound as the cathode active materialbecause the electrochemistries of different lithium metal compounds aregenerally incompatible in an operable lithium-ion electrochemical cell.However, scrap battery and electrochemical cell streams generallycomprise a mixture of lithium-ion electrochemical cells, which maycomprise different lithium metal compounds, and other types ofelectrochemical cells including nickel-metal hydride, nickel-zinc,nickel-cadmium, lead-acid, zinc-carbon, and/or alkaline. Therefore, itis important to separate the different lithium metal compounds from eachother in mixed electrochemical cell scrap streams, while maintaining thedifferent lithium metal compounds in their electrode-active structuraland chemical forms, in order to directly re-use the recovered lithiummetal compounds in the manufacture of new batteries. This isaccomplished in accordance with various embodiments described in thisspecification by utilizing the different magnetic susceptibilities ofdifferent lithium metal compounds, which are paramagnetic and,therefore, will exhibit different magnetization behavior when subjectedto an externally applied magnetic field.

As described, for example, in Julien et al., “Magnetic properties oflithium intercalation compounds,” Ionics, Volume 12, Number 1, 2006, pp.21-32, which is incorporated by reference into this specification,electrochemical cell-grade lithium metal compounds are generallyparamagnetic in the discharged and charged states and each possessdifferent magnetic susceptibility values. The differences in themagnetic susceptibility values of the different lithium metal compoundsused as cathode active materials allows the use of different magneticfield intensities and/or magnetic field gradients to differentiallymagnetize the lithium metal compound particles in mixed scrapelectrochemical cell streams. The differential magnetization of thedifferent lithium metal compounds in mixed scrap electrochemical cellstreams allows for the induction of attractive magnetic forces havingdifferent magnitudes between an externally applied magnetic field andthe different lithium metal compound particles. The different magnitudesof the induced magnetic forces allow for the selective separation of asingle lithium metal compound from a mixture comprising multiple lithiummetal compounds, graphite, and/or other electrochemical cell materials.In this manner, various constituents of mixed scrap electrochemical cellstreams comprising a plurality of electrode active materials may beefficiently separated to produce high purity electrode active materialconcentrates.

The embodiments described in this specification may produce purifiedconcentrates of electrode active materials, such as, for example,graphite and differentiated lithium metal compounds, which retain theiroriginal structural form (e.g., particle size and crystallography) andtheir original chemical composition as present in the scrapelectrochemical cells. The high purity separation of the electrodeactive materials enables the direct re-use of the recycled materials inthe production of new electrochemical cells, eliminating the need forfurther post-processing (e.g., hydrometallurgical or pyrometallurgicalprocesses) and synthesis (e.g., powder calcination) of the electrodeactive materials. In various non-limiting embodiments, a process for theseparation of materials from electrochemical cells comprises the stepsshown in FIG. 1, which is a flowchart diagram illustrating a process 10for the separation of materials from electrochemical cells.

Referring to FIG. 1, scrap electrochemical cells (e.g., scrap batteries)are input to the process 10 at step 12. The scrap electrochemical cellsare processed at step 14 to remove the anode materials and the cathodematerials from the other components comprising the electrochemical cellsforming the scrap, thereby removing the particulate electrode materials.The removal of the anode materials and the cathode materials at step 14may comprise one or more unit operations such as, for example,pre-sorting of different electrochemical cell chemistries; disassemblingof electrochemical cell modules (e.g., battery assemblies); dischargingelectrochemical cells; draining of electrolyte; solvent or supercriticalfluid extraction of electrolyte; pyrolysis or heat treatment tothermally degrade and remove plastics, electrolyte, and/or binder;crushing, milling, shredding, or otherwise comminuting electrochemicalcells; and screening, sieving, or otherwise classifying comminutedelectrochemical cell materials.

In various non-limiting embodiments, scrap batteries and otherelectrochemical cell devices may be pre-sorted based on their respectivecell chemistry, e.g., zinc-carbon, alkaline, lead-acid, nickel-zinc,nickel-cadmium, nickel-metal hydride, lithium-ion, and the like. One ormore of the pre-sorted electrochemical cell types may be input to theprocesses and systems described herein. In various non-limitingembodiments, the electrochemical cells input to the processes andsystems comprise lithium-ion electrochemical cells. Notwithstanding theutilization of an optional pre-sorting operation, it is expected thatsome electrochemical cells comprising operational chemistries other thanlithium-ion-based chemistries may be incidentally or intentionally inputto the separation processes and systems. An advantage of the processesand systems described in this specification is the capability ofproviding a robust separation and concentration of electrode activematerials from mixed electrochemical cell scrap comprising differenttypes of electrochemical cells.

In various non-limiting embodiments, scrap battery and otherelectrochemical cell modules and assemblies may be disassembled toremove the electrochemical cells from other components such aspackaging, housings, electrical leads, other circuitry, and the like.For example, some multi-cell batteries, such as those used in hybrid andfully electric automobiles, may be configured for facile separation intoindividual electrochemical cells. Alternatively, scrap batteries andother electrochemical cell devices may be processed in an as-receivedform.

In various non-limiting embodiments, scrap battery and otherelectrochemical cell modules and assemblies may be processed to ensurecomplete electrical discharge. Scrap electrochemical cells may bereceived in any charge state ranging from fully discharged to fullycharged. The charge state of the electrochemical cells may bedetermined, for example, by connecting a resistive load across theterminal electrodes of the battery and measuring the current flowingthrough the resistive load. If a test reveals that an electrochemicalcell device is not fully discharged, then a resistive load may beconnected across the terminals of the device for such time as to ensurecomplete discharge. In various other non-limiting embodiments, scrapelectrochemical cells may be soaked in an aqueous or non-aqueous saltsolution (e.g., aqueous sodium chloride brine solution) of sufficientconductivity to cause electrical discharge.

Scrap electrochemical cells generally comprise an electrolyte that mustbe removed from the devices before the electrode materials can beseparated from the other components comprising the electrochemicalcells. Liquid electrolytes may be drained or otherwise passively removedfrom scrap electrochemical cells. Alternatively, or in addition,electrolyte may be removed from scrap electrochemical cells using afluid displacement and/or solvent extraction operation in which theelectrochemical cells are breached and penetrated with a fluid thatphysically displaces and/or dissolves and washes out the electrolyte. Invarious non-limiting embodiments, scrap electrochemical cells may besubjected to a gaseous, liquid, or supercritical fluid displacementand/or extraction operation as described in U.S. Pat. Nos. 7,198,865;7,858,216; and 8,067,107; and in U.S. Patent Application Publication No.2011-0272331 A1, each of which is incorporated by reference into thisspecification.

In various non-limiting embodiments, scrap electrochemical cells may becomminuted to form a particulate mixture of electrochemical cellcomponents that can be classified by particle size. The comminution ofscrap electrochemical cells may be performed, for example, using acrushing, milling, and/or shredding operation. Examples of suitablecomminution equipment include, but are not limited to, vertical cuttingmills, hammer mills, knife mills, slitter mills, ball mills, pebblemills, and the like. The comminuted electrochemical cell components maythen be classified and separated based on particle size to remove andseparate plastic casing materials, steel or aluminum casing materials,plastic separator materials, circuit components, and other non-electrodematerials from the particulate electrode materials. The sizeclassification and separation of comminuted electrochemical cellmaterials may be performed, for example, using a screening or sievingoperation. Such unit operations may be performed, for example, usingmultiple differently-sized sieves, air tables, vibration screens, andlike equipment.

In various non-limiting embodiments, multiple comminution-classificationstages may be conducted in series to remove non-electrode materials fromthe particulate electrode active materials and to refine the electrodeactive material particle sizes by breaking-up agglomerates of electrodeactive material particles. Alternatively, or in addition, comminutedelectrochemical cell components may be subjected to a preliminarymagnetic separation operation to remove ferromagnetic and very highlyparamagnetic materials such as, for example, steel casing and housingmaterials. It is understood that a preliminary magnetic separationoperation to remove ferromagnetic and very highly paramagnetic materialsfrom comminuted electrochemical cells before the formation of a slurry(see step 16 in FIG. 1, described below) is different than the magneticseparation and concentration of electrode active materials (see steps18-24 in FIG. 1, described below).

Referring to FIG. 1, electrochemical cell black mass is the product ofthe one or more unit operations at step 14 comprising the removal ofanode and cathode materials. As used herein, the term “black mass”refers to the finest particulate fraction classified from comminutedelectrochemical cells. The black mass is a powder comprising electrodematerials including electrode active materials, polymeric binder,residual aluminum and copper current collection material, and otherresidual particulates. The chemical composition of black mass dependsupon the chemistry of the scrap electrochemical cells input to theprocess 10 at step 12. For example, in accordance with variousembodiments described in this specification, the black mass produced atstep 14 may comprise any material, or combination of materials, selectedfrom the group consisting of lead and lead compounds, zinc and zinccompounds, cadmium and cadmium compounds, copper, aluminum, nickeloxyhydroxide, nickel-metal hydride alloys, graphite, lithium metalcompounds, polymeric binder, and combinations of any thereof. Of thesematerials, aluminum, nickel oxyhydroxide, nickel-metal hydride alloys,and lithium metal compounds are paramagnetic and the others arediamagnetic.

The black mass produced at step 14 may be used to form a slurry at step16. As used herein, the term “slurry” refers to any fluidized suspensionor dispersion of black mass particles, including, for example, aqueousliquid slurries, non-aqueous liquid slurries, mixed-solvent liquidslurries, and gaseous slurries, i.e., pneumatic transport in pressurizedair, nitrogen (N₂), carbon dioxide (CO₂) and/or like gases. In variousnon-limiting embodiments, the production of a slurry comprisingelectrochemical cell black mass particles may comprise one or more unitoperations such as, for example, solvent wash treatment, water rinsetreatment, froth flotation treatment, mechanical dispersion, and/orultrasonic dispersion.

In various non-limiting embodiments, black mass may be treated with awash solvent to dissolve and remove polymeric electrode binder, such as,for example, polyvinylidene fluoride, from the electrode activematerials (e.g., graphite, lithium metal compounds, nickel oxyhydroxide,and the like). Suitable wash solvents include, for example,N-methyl-2-pyrrolidone, tetrathydrofuran, ethanol, dimethyl carbonate,diethylcarbonate, dimethyl acetamide, diethyl formamide, methyl isobutylketone, and combinations of any thereof. Alternatively, or in addition,black mass may be treated with a water rinse before, after, or insteadof a solvent wash treatment. Alternatively, or in addition, black massmay be heat treated or subject to a pyrolysis treatment. For example,black mass may be exposed to elevated temperatures in air or otheroxidizing environments. Heat or pyrolysis treatments may be performed atenvironmental temperatures of at least 300° C., for example.

In various non-limiting embodiments, black mass may be subjected to afroth floatation treatment to remove lead and lead compounds from theblack mass, which may be inadvertently or intentionally present due tothe presence of lead-acid batteries in the scrap electrochemical celldevices input to the processes and systems. For example, black mass maybe subjected to a froth floatation treatment as described in U.S. PatentApplication Publication No. 2011-0272331 A1, which is incorporated byreference into this specification. In various non-limiting embodiments,black mass comprising Pb(II) and Pb(IV) compounds may be suspended inwater in a froth flotation vessel with a froth flotation agent andsparged with air to entrain hydrophobically-modified lead compoundmaterials and float the lead-based materials out of the vessel, therebyremoving the lead-based materials from the black mass.

The production of a slurry comprising black mass particles may comprisethe dispersion or suspension of the black mass particles in a carrierfluid. Carrier fluids include liquids such as, for example, water,alcohols, hydrocarbons, condensed carbon dioxide, and the like, andgases such as, for example, air, nitrogen, carbon dioxide, and the like.In some embodiments, a slurry may comprise from 5 percent to 50 percent(by mass) of black mass solids content or any sub-range subsumedtherein, such as, for example, 10-40%, 20-40%, or 30-40% black masssolids by mass. In various non-limiting embodiments, the black massslurry may be subjected to an ultrasonic dispersion operation tobreak-up particle agglomerates and further refine the particle size. Invarious non-limiting embodiments, the production of an aqueous liquidslurry comprising black mass particles may use distilled and/ordeionized, pH-neutral water to maintain the chemistry of the constituentelectrode active material particles. The dispersion or suspension of theblack mass particles in a carrier fluid should employ appropriate mixingequipment to maintain particles in dispersion or suspension and avoidaccumulation of non-dispersed or non-suspended particles.

Referring to FIG. 1, the slurry comprising electrode active materialssuch as graphite, lithium metal compounds, and the like, is subjected toa magnetic field at step 18. The slurry is subjected to a magnetic fieldof sufficient magnetic field intensity and/or magnetic field gradient tomagnetize paramagnetic particles comprising the slurry. For example, themagnetic field may magnetize particles comprising at least one lithiummetal compound. The magnetization of particles comprising the slurryinduces a magnetic force between the magnetized particles and an activemagnetic surface in contact with the slurry at step 20. The attractivenature of the induced magnetic force separates the magnetized particlesfrom the slurry at step 22, for example, by pinning the magnetizedparticles to the active magnetic surface in contact with the slurry,thereby overcoming the fluid drag forces of the slurry carrier fluid andretaining the magnetized particles as a magnetic fraction while elutinga non-magnetic fraction. By controlling the magnetic field intensityand/or gradient, and the nature of the active magnetic surface,predetermined electrode active materials separated from the slurry maybe concentrated and purified to produce an electrode active materialconcentrate at step 24.

The magnetization, separation, and/or concentration of electrode activematerials from a black mass slurry may be performed using magneticseparation equipment such as, for example, high-intensity magneticfilters, wet high-intensity magnetic separators, and wet drumseparators. Such equipment is available, for example, from EriezManufacturing Company, Erie, Pa., USA. In addition,superconducting/high-gradient magnetic separation equipment comprisingsupercooled electromagnets may be used to maintain high magneticintensities.

High-intensity magnetic filters and wet high-intensity magneticseparators comprise high-intensity electromagnets and a magneticflux-converging matrix to concentrate paramagnetic materials. Theexternally applied magnetic field from the electromagnets induces amagnetization in the flux-converging matrix that produces a zone of highmagnetic gradient. Paramagnetic particles passing through the highmagnetic gradient zone are also magnetized, which induces an attractivemagnetic force between the magnetized particles and the flux-convergingmatrix, which functions as an active magnetic surface to which themagnetized particles may be pinned, thereby overcoming fluid drag forcesof a carrier fluid and retaining the magnetized particles as a magneticfraction while eluting a non-magnetic fraction. The retained magneticfraction may be collected from a high-intensity magnetic filter or wethigh-intensity magnetic separator by de-energizing the electromagnets,which removes the induced magnetic field and the induced attractiveforce between the retained particles and the flux-converging matrix, andflushing the particles from the equipment with clean carrier fluid.

FIG. 2 schematically illustrates a high-intensity magnetic filter/wethigh-intensity magnetic separator system 50, which may be used invarious non-limiting embodiments. The system 50 comprises twoelectromagnetic coils 52 a and 52 b in an opposed orientation across aseparation box 54. The opposed electromagnetic coils 52 a and 52 b arepositioned in a Helmholz-type coil orientation and provide magneticpoles between which an essentially uniform magnetic field isestablished. The externally applied magnetic field passes through theseparation box 54 and the magnetic flux-converging matrix 56. Themagnetic flux-converging matrix 56 is positioned within the separationbox 54 to intensify the magnetic field gradient within the separationbox 54 and to function as an active magnetic surface to which magnetizedparticles are pinned during a separation. The magnetic flux convergingmatrix 54 may comprise an expanded metal grid material. The magneticflux converging matrix 54 may also comprise grooved plates, steel balls,and/or steel wool, for example.

The separation box 54 comprises inlet port 63 and outlet port 65 for theflow of a slurry through the separation box 54 during operation. Theslurry is pumped, drained, or otherwise flowed through the separationbox 54 from a slurry feed 60. The system 50 operates by flowing theslurry through the separation box 54 and the magnetic flux-convergingmatrix 56 with the magnetic coils 52 a and 52 b in an energized state.The magnetic field established in the separation box 54 magnetizes themagnetic flux-converging matrix 56 intensifying the magnetic fieldgradient within the separation box 54. Magnetized particles in theslurry flowing through the separation box 54 are separated from theslurry by magnetic force between the particles and the active magneticsurfaces provided by the magnetic flux-converging matrix 56. Theseparated particles collect in the magnetic flux-converging matrix 56during operation and non-magnetic particles are carried through theseparation box 54 and the magnetic flux-converging matrix 56 by fluiddrag forces in the slurry flow. The non-magnetic fraction is collectedin collection vessel 66. The particles retained in the magneticflux-converging matrix 56 are flushed out of the separation box 54 byflowing clean carrier fluid from a clean carrier fluid feed 62 andthrough the separation box 54 after discontinuing the slurry flow fromslurry feed 60 and after de-energizing the electromagnetic coils 52 aand 52 b. The flushed magnetic fraction is collected in collectionvessel 68. The flow of slurry, clean carrier fluid, non-magneticfractions, and flushed magnetic fractions may be controlled, forexample, by manipulating valves 58 a, 58 b, 58 c, and 58 d, and othertransport equipment such as pumps (not shown).

Depending on the intensity of the magnetic field established in theseparation box 54 and the magnetic susceptibility of paramagneticmaterial comprising the slurry, paramagnetic particles may be magnetizedand pinned to the active magnetic surface provided by the magneticflux-converging matrix 56. Accordingly, the intensity of the magneticfield established in the separation box 54 may be controlled bycontrolling the current supplied to the electromagnetic coils 52 a and52 b, which in turn may be used to control the separation of electrodeactive materials comprising a slurry by retaining predeterminedparamagnetic compounds, such as lithium metal compounds, while passingnon-magnetic compounds such as graphite. This capability may be used toseparate and concentrate the various electrode active materialscomprising the slurry fed to system 50.

In various non-limiting embodiments, a process or system comprising ahigh-intensity magnetic filter or a wet high-intensity magneticseparator may be used to separate materials from electrochemical cellsin accordance with this specification. A process or system comprising ahigh-intensity magnetic filter or a wet high-intensity magneticseparator may be operated in a batch or semi-batch manner. For example,a slurry comprising multiple different electrode active materials suchas graphite and one or more lithium metal compounds may be fed to ahigh-intensity magnetic filter or a wet high-intensity magneticseparator operating at a magnetic field intensity sufficient to retain aparamagnetic electrode active material. The resulting magnetic fractionmay comprise a lithium metal compound concentrate, for example, and thenon-magnetic fraction may comprise graphite and lithium metal compoundspossessing lower magnetic susceptibility values than the magneticallyretained compound.

For example, if the slurry originally comprised two or more lithiummetal compounds having different magnetic susceptibility values, thenon-magnetic fraction comprising graphite and the lesser magneticallysusceptible lithium metal compounds may be fed to a high-intensitymagnetic filter or a wet high-intensity magnetic separator operating ata higher magnetic field intensity sufficient to retain the lithium metalcompound possessing the next largest magnetic susceptibility value butpassing the graphite and the lithium metal compounds possessing lowermagnetic susceptibility values. The resulting magnetic fraction maycomprise a second lithium metal compound concentrate and the resultingnon-magnetic fraction may comprise a graphite concentrate or a refinedmixture of graphite and lesser magnetically susceptible lithium metalcompounds. In this manner, the non-magnetic fractions may besequentially passed through a high-intensity magnetic filter or a wethigh-intensity magnetic separator operating at sequentially highermagnetic field intensities, thereby sequentially separating andconcentrating various electrode active materials based on theirsuccessively lower magnetic susceptibility values. Also, in this manner,additional non-lithium-based paramagnetic electrode active materialssuch as nickel oxyhydroxides or nickel metal hydride alloys may beseparated and concentrated from a feed slurry comprising a mixed blackmass isolated from multiple different electrochemical cell types such asnickel metal hydride and lithium-ion cells.

FIG. 3 schematically illustrates a non-limiting embodiment of a system50′ in which sequentially staged separation of multiple electrode activematerials from a feed slurry comprises a recycle line 70 that feeds thecollected non-magnetic fraction back into the separation box 54. Whilethe recycle feature is shown in FIG. 3 as a material transport line, itis understood that the recycle of non-magnetic fractions may beimplemented manually or using any suitable combination of materialtransport equipment in a batch or semi-batch operational mode.

FIG. 4 schematically illustrates a non-limiting embodiment of a system100 in which sequentially staged separation of multiple electrode activematerials from a feed slurry comprises multiple high-intensity magneticfilters and/or wet high-intensity magnetic separators 105 a, 105 b, and105 c fluidly connected in series and operating at sequentially highermagnetic field intensities. An initial slurry feed 106 is fed to a firstmagnetic separator 105 a where a first magnetic fraction is retainedcomprising the slurry constituent possessing the largest magneticsusceptibility value. The first magnetic fraction is subsequentlycollected as a first electrode active material concentrate. A firstnon-magnetic fraction passes the first magnetic separator 105 a and isfed to a second magnetic separator 105 b where a second magneticfraction is retained comprising the slurry constituent possessing thesecond largest magnetic susceptibility value. The second magneticfraction is subsequently collected as a second electrode active materialconcentrate. A second non-magnetic fraction passes the second magneticseparator 105 b and is fed to a third magnetic separator 105 c where athird magnetic fraction is retained comprising the slurry constituentpossessing the third largest magnetic susceptibility value. The thirdmagnetic fraction is subsequently collected as a third electrode activematerial concentrate. A third non-magnetic fraction passes the thirdmagnetic separator 105 c and may comprise a non-magnetic electrodeactive material concentrate, such as, for example, a graphiteconcentrate, that may be collected. Alternatively, the thirdnon-magnetic fraction may be fed to subsequent unit operations such asadditional magnetic separation stages for further refinement.

It is understood that any number of magnetic separation stages may beutilized in an implementation of the processes and systems described inthis specification, any number of which may be connected in series or inparallel, and any number of which may comprise recycle features asdescribed in connection with FIG. 3.

Drum separators comprise a stationary magnet assembly located within arotating drum positioned in a slurry tank. The externally appliedmagnetic field from the magnet assembly induces a magnetization in thedrum surface as it rotates past the magnet assembly, which produces azone of high magnetic gradient. Paramagnetic particles passing throughthe high magnetic gradient zone are also magnetized by the externallyapplied magnetic field, which induces an attractive magnetic forcebetween the magnetized particles and the magnetized drum surface whenthe surface is located adjacent to the magnet assembly. The drum surfacefunctions as an active magnetic surface to which the magnetizedparticles may be pinned, thereby overcoming fluid drag forces of aslurry carrier fluid and retaining the magnetized particles on the drumsurface while the drum surface is located adjacent to the magnetassembly. As the rotating drum surface proceeds away from the magnetassembly, the magnetic field weakens, the drum surface and pinnedparticles are de-magnetized, and the previously magnetized particlesdetach from the drum surface and elute as a magnetic fraction. Thebalance of the feed slurry elutes as a non-magnetic fraction.

FIGS. 5A and 5B schematically illustrate a concurrent tank drumseparator 150 a and a counter-rotation tank drum separator 150 b,respectively. As shown in FIG. 5A, the tank drum separator 150 acomprises a stationary magnet assembly 152 a located within a rotatingdrum 156 a positioned in a slurry tank 154 a. The externally appliedmagnetic field from the magnet assembly 152 a induces a magnetization inthe drum surface 156 a as it rotates past the magnet assembly 152 a,which produces a zone 163 a of high magnetic gradient. Paramagneticparticles passing through the high magnetic gradient zone 163 a are alsomagnetized by the magnet assembly 152 a, which induces an attractivemagnetic force between the magnetized particles and the magnetized drumsurface 156 a when the surface is located adjacent to the magnetassembly 152 a. The drum surface 156 a functions as an active magneticsurface to which the magnetized particles may be pinned, therebyovercoming fluid drag forces of a slurry carrier fluid and retaining themagnetized particles on the drum surface 156 a while the drum surface islocated adjacent to the magnet assembly 152 a. As the counterclockwiserotating drum surface 156 a proceeds away from the magnet assembly 152a, the magnetic field weakens, the drum surface and pinned particles arede-magnetized, and the previously magnetized particles detach from thedrum surface and elute as a magnetic fraction. The balance of the feedslurry elutes as a non-magnetic fraction. The counterclockwise rotationof the drum surface 156 a is generally concurrent with the direction ofslurry flow as indicated by arrows 165 a.

As shown in FIG. 5B, the tank drum separator 150 b comprises astationary magnet assembly 152 b located within a rotating drum 156 bpositioned in a slurry tank 154 b. The externally applied magnetic fieldfrom the magnet assembly 152 b induces a magnetization in the drumsurface 156 b as it rotates past the magnet assembly 152 b, whichproduces a zone 163 b of high magnetic gradient. Paramagnetic particlespassing through the high magnetic gradient zone 163 b are alsomagnetized by the magnet assembly 152 b, which induces an attractivemagnetic force between the magnetized particles and the magnetized drumsurface 156 b when the surface is located adjacent to the magnetassembly 152 b. The drum surface 156 b functions as an active magneticsurface to which the magnetized particles may be pinned, therebyovercoming fluid drag forces of a slurry carrier fluid and retaining themagnetized particles on the drum surface 156 b while the drum surface islocated adjacent to the magnet assembly 152 b. As the clockwise rotatingdrum surface 156 b proceeds away from the magnet assembly 152 b, themagnetic field weakens, the drum surface and pinned particles arede-magnetized, and the previously magnetized particles detach from thedrum surface and elute as a magnetic fraction. The balance of the feedslurry elutes as a non-magnetic fraction. The clockwise rotation of thedrum surface 156 b is generally counter-current with the direction ofslurry flow as indicated by arrows 165 b.

Depending on the intensity of the magnetic field established in the highmagnetic gradient zones 162 a and 163 b, and the magnetic susceptibilityof paramagnetic material comprising the slurry, paramagnetic particlesmay be magnetized and pinned to the active magnetic surface provided bythe drum surfaces 156 a and 156 b. Accordingly, the intensity of themagnetic field established in the high magnetic gradient zones 162 a and163 b may be used to control the separation of electrode activematerials comprising a slurry by retaining predetermined paramagneticcompounds, such as lithium metal compounds, while passing non-magneticcompounds such as graphite. This capability may be used to separate andconcentrate the various electrode active materials comprising the feedslurry.

In various non-limiting embodiments, a process or system comprising adrum separator may be used to separate materials from electrochemicalcells in accordance with this specification. A process or systemcomprising a drum separator may be operated in a continuous, batch, orsemi-batch manner. For example, a slurry comprising multiple differentelectrode active materials such as graphite and one or more lithiummetal compounds may be fed to a drum separator operating at a magneticfield intensity sufficient to pin and separate a paramagnetic electrodeactive compound from the slurry. The resulting magnetic fraction maycomprise a lithium metal compound concentrate, for example, and thenon-magnetic fraction may comprise graphite and lithium metal compoundspossessing lower magnetic susceptibility values than the magneticallyretained compound.

For example, if the slurry originally comprised two or more lithiummetal compounds having different magnetic susceptibility values, thenon-magnetic fraction comprising graphite and the lesser magneticallysusceptible lithium metal compounds may be fed to a drum separatoroperating at a higher magnetic field intensity sufficient to pin andseparate the lithium metal compound possessing the next largest magneticsusceptibility value but passing the graphite and the lithium metalcompounds possessing lower magnetic susceptibility values. The resultingmagnetic fraction may comprise a second lithium metal compoundconcentrate and the resulting non-magnetic fraction may comprise agraphite concentrate or a refined mixture of graphite and lessermagnetically susceptible lithium metal compounds. In this manner, thenon-magnetic fractions may be sequentially passed through a drumseparator operating at sequentially higher magnetic field intensities,thereby sequentially separating and concentrating various electrodeactive materials based on their successively lower magneticsusceptibility values. Also, in this manner, additionalnon-lithium-based paramagnetic electrode active materials such as nickeloxyhydroxides or nickel metal hydride alloys may be separated andconcentrated from a feed slurry comprising a mixed black mass isolatedfrom multiple different electrochemical cell types such as nickel metalhydride and lithium-ion cells.

FIG. 6 schematically illustrates a non-limiting embodiment of a system200 in which sequentially staged separation of multiple electrode activematerials from a feed slurry comprises multiple drum separators 250 a,250 b, and 250 c fluidly connected in series and operating atsequentially higher magnetic field intensities. An initial slurry feedis fed to a first drum separator 250 a where a first magnetic fractioncomprising the slurry constituent possessing the largest magneticsusceptibility value is separated from the slurry feed. The firstmagnetic fraction is collected as a first electrode active materialconcentrate. A first non-magnetic fraction passes the first drumseparator 250 a and is fed to a second drum separator 250 b where asecond magnetic fraction comprising the slurry constituent possessingthe second largest magnetic susceptibility value is separated from thefirst non-magnetic fraction. The second magnetic fraction is collectedas a second electrode active material concentrate. A second non-magneticfraction passes the second drum separator 250 b and is fed to a thirddrum separator 250 c where a third magnetic fraction comprising theslurry constituent possessing the third largest magnetic susceptibilityvalue is separated from the second non-magnetic fraction. The thirdmagnetic fraction is collected as a third electrode active materialconcentrate. A third non-magnetic fraction passes the third drumseparator 250 c and may comprise a non-magnetic electrode activematerial concentrate, such as, for example, a graphite concentrate, thatmay be collected. Alternatively, the third non-magnetic fraction may befed to subsequent unit operations such as additional drum separationstages for further refinement.

It is understood that any number of drum separation stages may beutilized in an implementation of the processes and systems described inthis specification, any number of which may be connected in series or inparallel (see FIG. 7). In addition, it is understood that differenttypes of magnetic separation equipment, such as drum separators,high-intensity magnetic filters, and/or wet high-intensity magneticseparators, may be utilized in an implementation of the processes andsystems described in this specification, any number and type of whichmay be connected in series or in parallel.

The non-limiting embodiments illustrated in FIGS. 4 and 6 utilize stagedmagnetic separations in which the successive stages utilize successivelyincreased magnetic field intensities to successively separate andconcentrate electrode active materials based on successively lowermagnetic susceptibility values. This manner of staged operation isgenerally illustrated in FIG. 8. However, it is understood that variousnon-limiting embodiments may operate in an opposite fashion, i.e.,successive stages utilizing successively decreased magnetic fieldintensities to successively separate and concentrate electrode activematerials based on successively higher magnetic susceptibility values.This manner of staged operation is generally illustrated in FIG. 9.

Referring to FIG. 8, a slurry comprising four electrode active materials(EAM¹, EAM², EAM³, and EAM⁴) is processed in accordance with variousnon-limiting embodiments to separate and concentrate the constituentelectrode active materials. EAM¹ is diamagnetic like graphite, forexample. EAM², EAM³, and EAM⁴ are paramagnetic like lithium metalcompounds and nickel oxyhydroxide, for example, and each electrodeactive material possesses successively greater magneticsusceptibilities, i.e., χ¹<χ²<χ³<χ⁴. The slurry is successively fed tothree magnetic separation stages, which may be implemented using anysuitable combination of magnetic separation equipment. The threesuccessive stages utilize successively higher magnetic fieldintensities, i.e., H¹<H²<H³. The non-magnetic fraction from Stage-1 andStage-2 are fed to Stage-2 and Stage-3, respectively. EAM⁴ (comprisingthe largest magnetic susceptibility value, χ⁴) is separated andconcentrated as the magnetic fraction at Stage-1 (comprising thesmallest magnetic field intensity, H¹). EAM³ (comprising the secondlargest magnetic susceptibility value, χ³) is separated and concentratedas the magnetic fraction at Stage-2 (comprising the second smallestmagnetic field intensity, H²). EAM² and EAM¹ (comprising the secondlowest and the lowest magnetic susceptibility values, respectively, χ²and χ¹) are separated and concentrated at Stage-3 (comprising thelargest magnetic field intensity H³). EAM² is concentrated in themagnetic fraction of Stage-3 and EAM¹ is concentrated in thenon-magnetic fraction of Stage-3.

Referring to FIG. 9, a slurry comprising four electrode active materials(EAM¹, EAM², EAM³, and EAM⁴) is processed in accordance with variousnon-limiting embodiments to separate and concentrate the constituentelectrode active materials. EAM¹ is diamagnetic like graphite, forexample. EAM², EAM³, and EAM⁴ are paramagnetic like lithium metalcompounds and nickel oxyhydroxide, for example, and each electrodeactive material possesses successively greater magneticsusceptibilities, i.e. χ¹<χ²<χ³<χ⁴. The slurry is successively fed tothree magnetic separation stages, which may be implemented using anysuitable combination of magnetic separation equipment. The threesuccessive stages utilize successively lower magnetic field intensities,i.e., H¹>H²>H³. The magnetic fraction from Stage-1 and Stage-2 are fedto Stage-2 and Stage-3, respectively. EAM¹ (comprising the lowestmagnetic susceptibility value, χ¹) is separated and concentrated as thenon-magnetic fraction at Stage-1 (comprising the largest magnetic fieldintensity, H¹). EAM² (comprising the second lowest magneticsusceptibility value, χ²) is separated and concentrated as thenon-magnetic fraction at Stage-2 (comprising the second largest magneticfield intensity, H²). EAM³ and EAM⁴ (comprising the second highest andthe highest magnetic susceptibility values, respectively, χ³ and χ⁴) areseparated and concentrated at Stage-3 (comprising the smallest magneticfield intensity H³). EAM⁴ is concentrated in the magnetic fraction ofStage-3 and EAM³ is concentrated in the non-magnetic fraction ofStage-3.

While FIGS. 8 and 9 illustrate three magnetic separation stages, it isunderstood that various non-limiting embodiments may utilize one, two,or any number of stages in series and/or in parallel. In addition, it isunderstood that embodiments comprising a plurality of magneticseparation stages may be implemented in continuous, batch, or semi-batchoperational modes using one or more magnetic separation units with orwithout recycle features. For example, rather than operating a pluralityof magnetic separation units in series, a single magnetic separationunit may operate with a recycle feature wherein the magnetic fieldintensity of the single unit is successively increased or decreased in astep-wise manner between given magnetic separation unit operations.

In various non-limiting embodiments, various operating parameters may bemanipulated to maximize the recovery and grade (i.e., concentration) ofelectrode active materials in the concentrates produced at the variousmagnetic separation stages. Such operating parameters include, forexample, the solids content of the black mass slurry, the composition ofthe slurry carrier fluid, the composition of the particulate electrodeactive materials and other constituents of the slurry, the magneticseparation equipment (e.g., high-intensity magnetic filters, wethigh-intensity magnetic separators, drum separators, and the like), themagnetic field intensity and magnetic field gradient induced in therespective magnetic separation units, the slurry flowrate through therespective magnetic separation units, the flowrate of wash fluids (e.g.,clean carrier fluids) through the respective magnetic separation units,the utilization of recycle streams, and like parameters. The variationof these and like parameters in a given implementation of the processesand systems described in this specification may be performed by personshaving ordinary skill in the art in accordance with this specificationand without undue experimentation. For example, by simultaneouslyadjusting the magnetic field intensity, magnetic field gradient, slurryflowrate, and wash fluid flowrate in a given magnetic separation unit,the separation and concentration of select paramagnetic particles may beachieved.

The non-limiting and non-exhaustive examples that follow are intended tofurther describe various non-limiting and non-exhaustive embodimentswithout restricting the scope of the embodiments described in thisspecification.

EXAMPLES Example-1: Magnetic Susceptibilities of Select Lithium MetalCompounds

The magnetic susceptibility values of select lithium metal compoundscommonly employed in lithium-ion electrochemical cells were determined.The lithium metal compounds LiCoO₂, LiMn₂O₄, LiFePO₄, LiNiCoMnO₂, andLiNi_(0.833)Co_(0.170)O₂ were analyzed. The magnetic susceptibilitieswere determined by measuring the mass magnetizations (M_(m) [emu/gram],i.e., the net magnetic dipole moments per unit mass) induced in samplesof the lithium metal compounds when placed in various magnetic fieldintensities (H [Oersteds]). The magnetizations were measured using asuperconducting quantum interface device (SQUID) magnetometer. Theresulting magnetization versus magnetic field intensity data was plottedfor each lithium metal compound, as shown in FIGS. 10 and 11. Leastsquares linear regression analysis was used to fit the data for eachlithium metal compound with a linear best fit curve. The mass magneticsusceptibility (χ_(m) [emu/gm-Oe]) of each lithium metal compound wascalculated as the slope of the respective linear best fit curves, inaccordance with the magnetization formula:M_(m)=χ_(m)H

The magnetic susceptibilities are reported in Table 2 and FIG. 12.

TABLE 2 Lithium metal compound (χ_(m) [m³/kg]) (χ_(m) [emu/gm-Oe])LiFePO₄ 4.82 × 10−3 6.064 × 10⁻⁵ LiMn₂O₄ 3.52 × 10−3 4.419 × 10⁻⁵LiNiCoMnO₂ 2.26 × 10−3 2.842 × 10⁻⁵ LiNiO_(0.833)Co_(0.170)O₂ 1.34 ×10−3 1.690 × 10⁻⁵ LiCoO₂ 8.91 × 10−5 1.124 × 10⁻⁶As shown in FIG. 12, the magnetic susceptibilities of each lithium metalcompound are sufficiently different to facilitate the magneticseparation, isolation, and concentration of each individual lithiummetal compound from a mixed black mass slurry comprising multipledifferent lithium metal compounds.

The procedure outlined in this Example for determining the magneticsusceptibilities of select lithium metal compounds may be used withoutundue experimentation to determine the relative magneticsusceptibilities of other paramagnetic constituents of black massmaterials isolated from mixed scrap electrochemical cells. This willallow for the design of magnetic separation, isolation, andconcentration processes for additional constituents in accordance withthe processes and systems described in this specification and withoutundue experimentation.

Example-2: Select Lithium Metal Compound Test Separations

The lithium metal compounds analyzed in Example 1 were used to performtest separations utilizing an Eriez L-4-20 High Intensity Wet MagneticSeparator (Eriez Manufacturing Company, Erie, Pa., USA). The EriezL-4-20 comprises two electromagnetic coils in an opposed orientationacross a stainless steel separation box. The opposed coils providemagnetic poles between which a magnetic field is established uponenergizing the coils such that the magnetic field is located within theseparation box. A magnetic flux-converging matrix is positioned withinthe separation box to intensify the magnetic field gradient within theseparation box and function as an active magnetic surface to whichmagnetized particles are pinned during a separation. The magneticflux-converging matrix may comprise an expanded metal material similarto a steel wool material. The Eriez L-4-20 uses standard expanded metalflux-converging matrices such as, for example, coarse grid (½ inch #13gauge) and medium grid (¼ inch #18 gauge). Coarse grid will handle feedswith particle sizes as great as 20 mesh. Medium grid should be used withparticles of 30 mesh or smaller particle sizes.

The Eriez L-4-20 separation box comprises inlet and outlet ports for theflow of slurry through the separation box during operation. The EriezL-4-20 operates by flowing a slurry through the separation box and themagnetic flux-converging matrix with the magnetic coils energized. Themagnetic field established in the separation box magnetizes the magneticflux-converging matrix intensifying the magnetic field gradient withinthe separation box. Ferromagnetic particles in a slurry flowing throughthe separation box are separated from the slurry by magnetic forcebetween the particles and the active magnetic surface provided by themagnetic flux-converging matrix. The separated particles collect in themagnetic flux-converging matrix during operation and non-magneticparticles are carried through the separation box and the magneticflux-converging matrix by fluid drag forces in the slurry flow. Theparticles collected in the magnetic flux-converging matrix are flushedout of the separation box by flowing water through the separation boxafter discontinuing the slurry flow and de-energizing theelectromagnetic coils.

Depending on the intensity of the magnetic field established in theseparation box and the magnetic susceptibility values of paramagneticmaterials comprising a slurry, paramagnetic particles may also bemagnetized and pinned to the active magnetic surface provided by themagnetic flux converging matrix in the Eriez L-4-20. This capability wasused to perform two test separations: (i) a separation of a mixture ofreagent grade LiCoO₂ and reagent grade LiMn₂O₄; and (ii) a separation ofa mixture of reagent grade LiCoO₂ and reagent grade LiFePO₄.

LiCoO₂ powder was mixed with LiMn₂O₄ and LiFePO₄ powders, respectively,at one-to-one (1:1) volumetric ratios. The LiCoO₂—LiMn₂O₄ powder mixtureand the LiCoO₂—LiFePO₄ powder mixture were used to form aqueous slurriescomprising the lithium metal compounds at a 5% solid content by mass byhand mixing under ambient conditions. The aqueous slurries weredouble-passed through the Eriez L-4-20 operating at 30%, 60%, and 90% ofmaximum magnetic field intensity, respectively. A #18 gauge medium gridexpanded metal mesh was used as the magnetic flux-converging matrix forthe test separations. The first passes separated the constituentparticles into magnetic fractions (which were pinned to the magneticflux-converging matrix) and non-magnetic fractions (which passed throughwith the slurry) at the predetermined magnetic field intensities. Thenon-magnetic fractions from the first passes were fed through the EriezL-4-20 for second passes. After the second passes, the Eriez L-4-20 wasde-energized and the magnetic fractions were collected with a waterflush. A water flush was also used in between the first passes and thesecond passes (while the Eriez L-4-20 was energized) to ensure that anyentrained non-magnetic particles were removed from the first passmagnetic fraction.

The weight percentage recovery and concentration of the cobalt andeither manganese or iron, as applicable, were calculated for themagnetic and non-magnetic fractions for each slurry separated using theEriez L-4-20 operating at 30%, 60%, and 90% of maximum magnetic fieldintensity (approximately 0.6 Tesla, 1.2 Tesla, and 1.8 Tesla,respectively). The weight percentage recoveries were also calculated forthe entire lithium metal compounds. The weight percentage recoveries andconcentrations were calculated with data obtained usinginductively-coupled plasma atomic emission spectroscopy (ICP-AES). Theresults are reported in Tables 3 and 4 and FIGS. 13-20.

TABLE 3 Mag Element weight percentage concentration and percentageSample Field increase/decrease relative to feed Feed Fraction IntensityLi +/−Li Co +/−Co Mn +/−Mn Fe +/−Fe LiMn₂O₄ + Feed — 7.00 — 25.30 —42.00 — — — LiCoO₂ Mag 90% 5.45 −22.19 12.72 −49.72 59.22 41.01 — —Non-mag 90% 7.13 1.85 45.77 80.92 24.48 −41.72 — — Feed — 7.00 — 25.30 —42.00 — — — Mag 60% 5.43 −28.87 15.25 −65.86 53.83 21.97 — — Non-mag 60%7.65 9.24 57.30 126.48 16.77 −60.08 — — Feed — 7.00 — 25.30 — 42.00 — —— Mag 30% 5.60 −20.01 15.78 −37.62 56.11 33.59 — — Non-mag 30% 6.30−10.01 38.85 53.54 23.60 −43.81 — — LiFePO₄ + Feed — 6.45 — 45.81 — — —8.46 — LiCoO₂ Mag 90% 7.26 12.65 44.88 −2.04 — — 16.15 90.74 Non-mag 90%8.51 32.00 67.93 48.28 — — 5.63 −33.48 Feed — 6.45 — 45.81 — — — 8.46 —Mag 60% 7.26 12.65 47.29 3.22 — — 13.77 62.71 Non-mag 60% 8.51 32.0066.13 44.35 — — 5.53 −34.66 Feed — 6.45 — 45.81 — — — 8.46 — Mag 30%7.41 14.89 46.10 0.63 — — 15.46 82.60 Non-mag 30% 8.47 31.39 63.16 37.87— — 6.15 −27.35

TABLE 4 Sample Mag Field Recovery (weight percentage) Feed FractionIntensity LiMn₂O₄ LiCoO₂ LiFePO₄ LiMn₂O₄ + Feed — 100.00 100.00 100.00LiCoO₂ Mag 90% 74.43 25.06 — Non-mag 90% 7.45 74.94 — Feed — 100.00100.00 100.00 Mag 60% 83.79 30.01 — Non-mag 60% 7.39 69.99 — Feed —100.00 100.00 100.00 Mag 30% 70.34 28.84 — Non-mag 30% 7.92 71.16 —LiFePO₄ + Feed — 100.00 100.00 100.00 LiCoO₂ Mag 90% — 29.22 64.19Non-mag 90% — 70.78 35.81 Feed — 100.00 100.00 100.00 Mag 60% — 35.8266.03 Non-mag 60% — 64.18 33.97 Feed — 100.00 100.00 100.00 Mag 30% —20.55 47.11 Non-mag 30% — 79.45 52.89

As shown in Tables 3 and 4, and FIGS. 13-20, good separation andconcentration of the lithium metal compounds was achieved using thedifferent magnetic susceptibility values of the respective materials.

Example-3: Battery Electrode Active Material Test Separation

A magnetic separation using an Eriez L-4-20 High Intensity Wet MagneticSeparator (Eriez Manufacturing Company, Erie, Pa., USA) was performedusing the electrode active materials of prismatic pouch lithium-ioncells (AMP20™, A123 Systems, Inc., Waltham, Mass., USA). The mass anddimensions of the cells were measured and averaged 491 grams and 8.9inches by 6.4 inches by 0.65 inches. The cells were examined with avoltmeter to determine the electrical potential of the cells. A resistorwas clamped to the leads of each cell for a period of time to ensurefull electrical discharge. The cells were placed in a hermeticallysealed glove box and purged with nitrogen for 4 hours to ensure theremoval of oxygen from the glove box.

In the resulting inert atmosphere in the glove box, two prismatic pouchcells were disassembled by hand. Three edges of the cell pouch (top,right side, and bottom) were cut using knife taking care to not cut intothe anodes or cathodes. The cathode comprised a lithium iron phosphateactive material on an aluminum current collecting plate. The anodecomprised graphite on a copper current collecting plate. The electrolytecomprised an ethylene-carbonate based carrier fluid, which evaporatedduring disassembly. The anodes and cathodes were peeled from theseparator sheets, cut from the electrical leads, removed, and stored inseparate containers.

The anodes and cathodes were washed with isopropyl alcohol afterseparation from the pouch cells to remove residual electrolyte andcarrier fluid. The anodes and cathodes were then washed with water. Themasses and dimensions of the anode sheets were measured and averaged 9.5grams and 7.65 inches by 5.875 inches per sheet. The masses anddimensions of the cathode sheets were measured and averaged 6.7 gramsand 7.75 inches by 5.875 inches per sheet. The average total mass of theanodes was 202.0 grams, and the average total mass of the cathodes was175.5 grams, per pouch cell. The aluminized pouch, tabs, and separatorsheets had a mass of 54.3 grams. The total mass of the disassembledpouch cell was measured at 429.3 grams. The difference in masses betweena disassembled pouch and an intact pouch may be due to the removal ofelectrolyte and electrolyte carrier fluid, which typically takes upabout 12%-14% of the total mass of a prismatic pouch type lithium-ioncell. These data are reported in Table 5.

TABLE 5 WHOLE (Average Values) Mass Dimensions (in) g Height Width DepthPouch 491 8.9 6.4 0.65 DISASSEMBLED Propor- x1 Approx. # Mass tionDimensions (in) Sheet of Sheets g % Height Width g per pouch* Anode202.0 41.1% 7.625 5.875 9.5 21 Cathode 175.5 35.7% 7.75 5.875 6.7 26Pouch and 54.3 11.1% Separator Electrolyte 59.2 12.1% Amnt Calcd CalcSum 491.0 100.0% *Based on Weight

The isolated anodes and cathodes were processed separately butidentically. Each electrode sheet was shredded using a standard papershredder. The shredded electrodes were ground in a standard foodprocessor. These devices provided laboratory-scale operation similar topilot-scale or full-scale operation of a knife mill or slitter mill anda pebble mill or ball mill, respectively. The shredding andgrinding/milling process liberated approximately 75% of the electrodeactive materials (comprising graphite anode active materials and lithiumiron phosphate cathode active material) from the aluminum and coppercomponents of the electrodes. The electrode active materials werescreened through a 40-mesh screen to remove aluminum and copperparticulate contaminants from the shredding and grinding/millingoperations. The resulting anode and cathode black mass materials werewashed with de-ionized water.

The separately processed anode and cathode black mass materials weremixed in a 1.0-to-2.5 anode-to-cathode material ratio. Approximately 94grams of the mixed black mass material and 630 grams of de-ionized waterwere used to make a 15% solids content slurry. The slurry wasmagnetically separated using the Eriez L-4-20 operating at 30%, 60%, and90% of maximum magnetic field intensity (approximately 0.6 Tesla, 1.2Tesla, and 1.8 Tesla, respectively). A #18 gauge medium grid expandedmetal mesh was used as the magnetic flux converging matrix for the testseparation. The test separation was designed to sequentially separatethe strongest to weakest magnetically susceptible particles. In thismanner, ferromagnetic materials would not obstruct the mesh and/orentrain non-magnetic particles in the magnetic fraction.

Initially, the slurry was fed to the magnetic separator operating at 30%magnetic field intensity to pin any ferromagnetic and stronglyparamagnetic particles to the magnetic flux converging matrix, therebyseparating the magnetized particles from the slurry using the magneticforce between the magnetized particles and an active magnetic surface incontact with the slurry. The non-magnetic fraction passed through theseparation box and was collected in a container. After thoroughlyrinsing the pinned magnetic fraction with excess water, the collectioncontainer was changed, the coils de-energized, and the magnetic fieldremoved. The pinned magnetic fraction captured by the 30% intensityfield was washed out of the magnetic flux converging matrix andseparation box with de-ionized water and the first magnetic fraction wassaved for further analysis.

In like manner, the non-magnetic fraction from the first (30% fieldintensity) pass was fed through the magnetic separator operating at 60%magnetic field intensity, which resulted in a second magnetic fractionand a second non-magnetic fraction. Again, in like manner, thenon-magnetic fraction from the second (60% field intensity) pass was fedthrough the magnetic separator operating at 90% magnetic fieldintensity, which resulted in a third magnetic fraction and a thirdnon-magnetic fraction. Accordingly, the test separation produced a totalof four test fractions: three magnetic fractions corresponding to 30%,60%, and 90% field intensity, respectively, and a non-magnetic fractioncorresponding to the third non-magnetic fraction that passed through theseparator at 90% field intensity. The weight percentage recovery andconcentration of the lithium, iron, phosphorus, and carbon wascalculated for the four test fractions. The results are reported inTables 6-8 and FIGS. 21-25 and showed a staged or cumulative separationand concentration of the anode and cathode active materials.

TABLE 6 Weight Amount Concentrations [wt %] Sample # Description gramswt % Al Cu Fe Li P C 822 Anode: Cu - 26.8 28.5 0.35 0.64 0.09 0.00 0.77100.00 Carbon 823 Cathode: 67.2 71.5 0.36 0.14 34.08 2.37 16.96 7.04Al—LiFePO₄ Mixed Feed 94 100.0 0.36 0.28 24.39 1.70 12.34 33.54 824 30%Magnetic 9.2 9.82 0.34 0.17 34.64 2.70 17.41 7.80 825 60% Magnetic 18.319.53 0.44 0.18 30.28 1.99 15.26 8.37 826 90% Magnetic 25.8 27.53 0.470.18 34.20 2.52 17.10 10.59 827 Non-Magnetic 40.4 43.12 0.68 0.35 13.631.10 7.48 65.04 Calculated 93.7 100.00 0.54 0.25 24.61 1.82 12.62 33.36Mixed Feed

TABLE 7 Weight Amount Cumulative Amount [grams] Sample # Descriptiongrams wt % Al Cu Fe Li P C 822 Anode: Cu - 26.8 28.5 0.095 0.172 0.0250.000 0.207 26.800 Carbon 823 Cathode: 67.2 71.5 0.239 0.092 22.9031.594 11.396 4.731 Al—LiFePO₄ Mixed Feed 94 100.0 0.334 0.264 22.9281.594 11.602 31.531 824 30% Magnetic 9.2 9.82 0.031 0.015 3.187 0.2491.602 0.717 825 60% Magnetic 18.3 19.53 0.111 0.048 8.729 0.613 4.3942.250 826 90% Magnetic 25.8 27.53 0.233 0.093 17.552 1.262 8.807 4.983827 Non-Magnetic 40.4 43.12 0.276 0.141 5.507 0.445 3.021 26.275Calculated 93.7 100.00 0.510 0.234 23.059 1.708 11.827 31.258 Mixed Feed

TABLE 8 Sample # Weight Amount Recovery [%] — Description grams wt % AlCu Fe Li P C 822 Anode: Cu - 26.8 28.5 — — — — — — Carbon 823 Cathode:67.2 71.5 — — — — — — Al—LiFePO₄ — Mixed Feed 94 100.0 152.72 88.88100.57 107.13 101.94 99.13 824 30% Magnetic 9.2 9.82 9.30 5.78 13.9015.59 13.80 2.28 825 60% Magnetic 18.3 19.53 33.25 18.06 38.07 38.4837.87 7.14 826 90% Magnetic 25.8 27.53 69.89 35.32 76.55 79.19 75.9015.80 827 Non-Magnetic 40.4 43.12 82.83 53.56 24.02 27.94 26.04 83.33 —Calculated 93.7 100.00 100.00 100.00 100.00 100.00 100.00 100.00 MixedFeed — 30% Magnetic — — 6.09 6.50 13.82 14.55 13.54 2.30 — 60% Magnetic— — 21.77 20.31 37.85 35.92 37.15 7.20 — 90% Magnetic — — 45.77 39.7476.12 73.92 74.46 15.94 — Non-Magnetic — — 54.23 60.26 23.88 26.08 25.5484.06

The first pass at 30% field intensity (approximately 0.6 Tesla) retained9.82 weight percent of the slurry solids, the second pass at 60% fieldintensity (approximately 1.2 Tesla) retained 19.53 weight percent of theslurry solids, the third pass at 90% field intensity (approximately 1.8Tesla) retained 27.53 weight percent of the slurry solids, and theremaining 43.12 weight percent was collected as the non-magneticfraction. The graphite carbon anode active material was separated fromthe cathode active material in the non-magnetic fraction with a recoveryof 83% at a concentration of 65 weight percent. The lithium ironphosphate cathode active material was separated from the anode activematerial in the 90% magnetic fraction with a recovery of 75% at aconcentration of 17% based on mass of phosphorus. Analogous recovery andconcentration percentages were also observed based on the masses oflithium and iron.

Example-4: Lithium-Ion Electrochemical Cell Recycle Processes

An exemplary lithium-ion electrochemical cell recycle process and system300 is shown in FIG. 26. Scrapped electrochemical cell devices arecollected in storage bin 302. The collected devices are sorted intolithium-ion devices and non-lithium-ion devices (e.g., devicescomprising lead-acid and nickel metal hydride chemistries) in unitoperation 304. The pre-sorted lithium-ion devices are dissembled in unitoperation 306 into lithium-ion cells and non-cell components. Thelithium-ion cells are penetrated with an extraction solvent, such assupercritical carbon dioxide, for example, in extraction operation 308.The extraction removes lithium-ion electrolyte from the cells. Theextracted cells are comminuted into particles in comminuting operation310 (e.g., one or more of a knife mill, slitter mill, ball mill, pebblemill, and the like). The comminuted cells are classified inclassification operation 312 (e.g., one or more sieving/screening unitoperations). The classification operation 312 separates anode andcathode materials into a black mass comprising graphite, LiFePO₄,LiMn₂O₄, and LiCoO₂. The black mass is washed and/or rinsed with a washand/or rinse solvent in unit operation 314.

The washed and/or rinsed black mass is mixed with a carrier fluid inunit operation 316 to produce a slurry. The slurry is fed to a firstdrum separator 350 a where the most magnetically susceptible electrodeactive material (LiFePO₄) is separated and concentrated in a magneticfraction. The non-magnetic fraction from the first drum separator 350 a(comprising graphite, LiMn₂O₄, and LiCoO₂) is fed to a second drumseparator 350 b operating at a higher magnetic field intensity than thefirst drum separator 350 a. The second most magnetically susceptibleelectrode active material (LiMn₂O₄) is separated and concentrated in amagnetic fraction in the second drum separator 350 b. The non-magneticfraction from the second drum separator 350 b (comprising graphite andLiCoO₂) is fed to a third drum separator 350 c operating at a highermagnetic field intensity than the first drum separator 350 a and thesecond drum separator 350 b. The third most magnetically susceptibleelectrode active material (LiCoO₂) is separated and concentrated in amagnetic fraction in the third drum separator 350 c, and thenon-magnetic graphite is separated and concentrated in a non-magneticfraction in the third drum separator 350 c. Accordingly, the three drumseparators operate in the manner described in connection with FIG. 8.FIG. 27 illustrates an analogous process and system 300′ that operatesin the manner described in connection with FIG. 9 (i.e., with decreasingmagnetic field intensities in succeeding magnetic separationoperations).

The graphite, LiFePO₄, LiMn₂O₄, and LiCoO₂ concentrates produced inprocess and system 300 and 300′ may be used to manufacture newlithium-ion electrochemical cell devices. The process and system 300 and300′ may also be modified, for example, to comprise high-intensitymagnetic filters, wet high-intensity magnetic separators, or likemagnetic separation equipment. Additional magnetic separation stages maybe incorporated into the process and system as illustrated in FIG. 28(increased magnetic field intensities in successive stages) and FIG. 29(decreased magnetic field intensities in successive stages), forexample. The process and system 300 and 300′ may also be modified, forexample, to comprise various additional unit operations as describedabove, such as, for example, electrical discharge operations (e.g.,resistive loading or soaking in an aqueous or non-aqueous saltsolution); a preliminary magnetic separation operation to removeferromagnetic and very highly paramagnetic materials such as, forexample, steel casing and housing materials; milling of black massparticles after liberation from other electrochemical cell components; apyrolysis or heat treatment of black mass before slurry formation; afroth floatation treatment to remove lead and lead compounds from theblack mass; a froth floatation treatment to remove diamagnetic materialsfrom the final non-magnetic fraction of the staged magnetic separations;and an ultrasonic dispersion operation to break-up particle agglomeratesand further refine the particle size when forming black mass slurry.

Example-5: Mixed Secondary Battery Recycle Process

An exemplary mixed electrochemical cell recycle process and system 400is shown in FIG. 30. Scrapped electrochemical cell devices are collectedin storage bin 402. The collected devices are sorted into lead-aciddevices and non-lead-acid devices in unit operation 404. The pre-sortedno-lead-acid devices are dissembled in unit operation 406 intoelectrochemical cells and non-cell components. The electrochemical cellsare penetrated with an extraction solvent, such as supercritical carbondioxide, for example, in extraction operation 408. The extractionremoves electrolyte from the cells. The extracted cells are comminutedinto particles in comminuting operation 410 (e.g., one or more of aknife mill, slitter mill, ball mill, pebble mill, and the like). Thecomminuted cells are classified in classification operation 412 (e.g.,one or more sieving/screening unit operations). The classificationoperation 412 isolates anode and cathode materials into a black masscomprising graphite, lithium metal compounds, nickel metal hydridealloys, nickel oxyhydroxide, and/or various other electrode activematerials. The black mass is washed and/or rinsed with a wash and/orrinse solvent in unit operation 414.

The washed and/or rinsed black mass is mixed with a carrier fluid inunit operation 416 to produce a slurry. The slurry is fed to a firstdrum separator 450 a where the most magnetically susceptible electrodeactive material is separated and concentrated in a first magneticfraction. A number of staged magnetic separations are conducted in whichthe non-magnetic fraction of the preceding stage is fed as a slurry tothe succeeding stage. In the final (n^(th)) stage, a final (n^(th))magnetic fraction is separated from a final (n^(th)) non-magneticfraction in final drum separator 450 n. The multiple drum separatorsoperate in the manner described in connection with FIGS. 8 and 28 (i.e.,with increasing magnetic field intensities in succeeding magneticseparation operations), but may also be operated in the manner describedin connection with FIGS. 9 and 29 (i.e., with decreasing magnetic fieldintensities in succeeding magnetic separation operations). The 1^(st)through the n^(th) magnetic fractions may comprise electrode activematerial concentrates. The n^(th) non-magnetic fraction may be furtherprocessed to separate diamagnetic constituents such as, for example,graphite, zinc, cadmium, copper, lead, and related compounds. Theseparation of these diamagnetic materials may be performed, for example,using a froth flotation operation as described in U.S. PatentApplication Publication No. 2011-0272331 A1, which is incorporated byreference into this specification.

The electrode active material concentrates produced in process andsystem 400 may be used to manufacture new electrochemical cell devices.The process and system 400 may also be modified, for example, tocomprise high-intensity magnetic filters, wet high-intensity magneticseparators, or like magnetic separation equipment. The process andsystem 400 may also be modified, for example, to comprise variousadditional unit operations as described above, such as, for example,electrical discharge operations (e.g., resistive loading or soaking inan aqueous or non-aqueous salt solution, a preliminary magneticseparation operation to remove ferromagnetic and very highlyparamagnetic materials such as, for example, steel casing and housingmaterials, a froth floatation treatment to remove lead and leadcompounds from the black mass, and an ultrasonic dispersion operation tobreak-up particle agglomerates and further refine the particle size whenforming black mass slurry.

Using magnetic separation is a relatively inexpensive way to efficientlyseparate electrode active materials from each other creating aprofitable product. In comparison to hydrometallurgy, the cost savingscan be found in the fact that the process and systems described in thisspecification do not require chemical extraction/leachant solutions andprecipitation, deposition, or electrowinning operations. In comparisonto pyrometallurgy, lower costs are realized by avoiding the use ofenergy intensive smelting operations to reduce the material to its basemetals. In contrast to both hydrometallurgy and pyrometallurgyprocesses, the processes and systems described in this specificationdirectly produce recycled electrode active material that can be directlyre-used in new electrochemical cell manufacturing.

This specification has been written with reference to variousnon-limiting and non-exhaustive embodiments. However, it will berecognized by persons having ordinary skill in the art that varioussubstitutions, modifications, or combinations of any of the disclosedembodiments (or portions thereof) may be made within the scope of thisspecification. Thus, it is contemplated and understood that thisspecification supports additional embodiments not expressly set forthherein. Such embodiments may be obtained, for example, by combining,modifying, or reorganizing any of the disclosed steps, step sequences,components, elements, features, aspects, characteristics, limitations,and the like, of the various non-limiting embodiments described in thisspecification. In this manner, Applicant(s) reserve the right to amendthe claims during prosecution to add features as variously described inthis specification, and such amendments comply with the requirements of35 U.S.C. § 112, first paragraph, and 35 U.S.C. § 132(a).

What is claimed is:
 1. A process for the separation of materials fromelectrochemical cells, the process comprising: flowing a slurrycomprising electrode active material particles through a magneticseparator, wherein the electrode active material particles compriseparamagnetic particles comprising a lithium metal oxide compound and/ora lithium metal phosphate compound; subjecting the slurry to a magneticfield of sufficient magnetic field strength to magnetize theparamagnetic particles; and separating the magnetized particles from theslurry using magnetic force between the magnetized particles and anactive magnetic surface in contact with the slurry in the magneticseparator.
 2. The process of claim 1, further comprising flowing theslurry through a plurality of staged magnetic separators connected inseries.
 3. The process of claim 2, wherein each successive magneticseparator comprises a higher magnetic field intensity or a highermagnetic field gradient, and wherein each successive magnetic separatorseparates an electrode active material comprising a lower magneticsusceptibility value.
 4. The process of claim 2, wherein each successivemagnetic separator comprises a lower magnetic field intensity or a lowermagnetic field gradient, and wherein each successive magnetic separatorseparates an electrode active material comprising a higher magneticsusceptibility value.
 5. The process of claim 2, wherein the pluralityof staged magnetic separators are selected from the group consisting ofhigh-intensity magnetic filters, wet high-intensity magnetic separators,drum separators, and combinations of any thereof.
 6. The process ofclaim 1, wherein the magnetic separator comprises a high-intensitymagnetic filter, a wet high-intensity magnetic separator, or a drumseparator.
 7. The process of claim 1, wherein the lithium metal oxidecompound and/or the lithium metal phosphate compound comprises acompound of the formula:LiM_(x)N_(z) wherein M is one or more metals selected from the groupconsisting of Co, Mn, Ni, Fe, and Al, wherein N is an inorganic counterion selected from the group consisting of O₂ ²⁻ and PO₄ ³⁻, wherein xranges from greater than zero to two, and wherein z ranges from one tofive.
 8. The process of claim 1, wherein the lithium metal oxidecompound and/or the lithium metal phosphate compound comprises a lithiummetal oxide compound of the formula:LiNi_(1-y)Co_(y)O₂ wherein y ranges from zero to
 1. 9. The process ofclaim 1, wherein the lithium metal oxide compound and/or the lithiummetal phosphate compound comprises LiCoO₂, LiMn₂O₄, LiFePO₄, LiNiO₂,LiNiCoMnO₂, LiNi_(1/3)Co_(1/3)Al_(1/3)O₂, LiNi_(0.8)Co_(0.2)O₂, orLiNiO_(0.833)Co_(0.170)O₂, or a combination of any thereof.
 10. Aprocess for the separation of materials from electrochemical cells, theprocess comprising: providing electrode active material comprising alithium metal oxide compound and/or a lithium metal phosphate compoundrecovered from lithium ion electrochemical cells; forming a slurrycomprising particles of the electrode active material; subjecting theslurry to a magnetic field of sufficient magnetic field intensity tomagnetize particles in the slurry; and separating the magnetizedparticles from the slurry using magnetic force induced between themagnetized particles and an active magnetic surface in contact with theslurry.
 11. The process of claim 10, wherein particles comprising thelithium metal oxide compound and/or the lithium metal phosphate compoundare magnetically separated from graphite particles.
 12. The process ofclaim 10, wherein particles comprising the lithium metal oxide compoundand/or the lithium metal phosphate compound are magnetically separatedfrom particles comprising a nickel oxyhydroxide compound and/or a nickelmetal hydride alloy.
 13. The process of claim 10, wherein the electrodeactive material comprises two or more lithium metal oxide compounds, andthe separated particles comprise one of the two or more lithium metaloxide compounds.
 14. The process of claim 13, further comprisingmagnetically separating the particles comprising the two or more lithiummetal compounds from graphite particles.
 15. The process of claim 13,further comprising magnetically separating the particles comprising thetwo or more lithium metal compounds from particles comprising a nickeloxyhydroxide compound and/or a nickel metal hydride alloy.
 16. Theprocess of claim 10, wherein the lithium metal oxide compound and/or thelithium metal phosphate compound comprises a compound of the formula:LiM_(x)N_(z) wherein M is one or more metals selected from the groupconsisting of Co, Mn, Ni, Fe, and Al, wherein N is an inorganic counterion selected from the group consisting of O₂ ²⁻ and PO₄ ³⁻, wherein xranges from greater than zero to two, and wherein z ranges from one tofive.
 17. The process of claim 10, wherein the lithium metal oxidecompound and/or the lithium metal phosphate compound comprises a lithiummetal oxide compound of the formula:LiNi_(1-y)Co_(y)O₂ wherein y ranges from zero to
 1. 18. The process ofclaim 10, wherein the lithium metal oxide compound and/or the lithiummetal phosphate compound comprises LiCoO₂, LiMn₂O₄, LiFePO₄, LiNiO₂,LiNiCoMnO₂, LiNi_(1/3)Co_(1/3)Al_(1/3)O₂, LiNi_(0.8)Co_(0.2)O₂, orLiNiO_(0.833)Co_(0.170)O₂, or a combination of any thereof.
 19. Theprocess of claim 10, comprising flowing the slurry through a drumseparator, wherein the magnetic force is induced between the magnetizedparticles and a magnetized surface of a drum in contact with the slurry.20. The process of claim 10, comprising flowing the slurry through ahigh-intensity magnetic filter or a wet high-intensity magneticseparator, wherein the magnetic force is induced between the magnetizedparticles and a magnetic flux-converging matrix in contact with theslurry.
 21. The process of claim 10, comprising flowing the slurrythrough a plurality of staged magnetic separators connected in series,wherein magnetic force is induced between the magnetized particles inthe slurry and an active magnetic surface in contract with the slurry ineach magnetic separator, and wherein one electrode active material isseparated and concentrated in each stage.
 22. The process of claim 21,wherein the plurality of staged magnetic separators are selected fromthe group consisting of high-intensity magnetic filters, wethigh-intensity magnetic separators, drum separators, and combinations ofany thereof.
 23. The process of claim 21, wherein each successivemagnetic separator comprises a higher magnetic field intensity or ahigher magnetic field gradient, and wherein each successive magneticseparator separates an electrode active material comprising a lowermagnetic susceptibility value.
 24. The process of claim 21, wherein eachsuccessive magnetic separator comprises a lower magnetic field intensityor a lower magnetic field gradient, and wherein each successive magneticseparator separates an electrode active material comprising a highermagnetic susceptibility value.
 25. The process of claim 10, furthercomprising, before forming the slurry: comminuting lithium ionelectrochemical cells; and screening the comminuted lithium ionelectrochemical cells to separate the particles of the electrode activematerial from other components of the lithium ion electrochemical cells.26. The process of claim 10, further comprising, before forming theslurry, washing the electrode active material particles with a washsolvent to dissolve and remove polymeric electrode binder.
 27. Theprocess of claim 10, wherein forming the slurry comprises mixing theparticles of the electrode active material with a carrier fluid.
 28. Theprocess of claim 10, further comprising, before removing the electrodeactive material from the lithium ion electrochemical cells, penetratingthe electrochemical cells with an extraction solvent and removing aportion of electrolyte.
 29. The process of claim 28, wherein theextraction solvent comprises supercritical carbon dioxide.